System of tone-signaling and impulsing



April 11, 1939. R TRECHCINSKI 2,153,654

' SYSTEM 01 TONE-SIGNALING AND IMPULSING Fili June 12, 1956 5 Sheets-Sheet 1 m-M-m 0 so ms 0'1020 3040506070w'100ms April 11, 1939. R. TRECHCINSKI 2,153,654

SYSTEM OF TONE'SIGNALING AND IMPULSING Filed June 12, 1936 3 Sheets-Sheet 2 "b 1, Fal

Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE SYSTEM OF TONE-SIGNALING AND IMPULSING Application June 12, 1936, Serial No. 84,915

' In Poland June 15, 1935 6 Claims.

I have filed an application in Poland on June 15, 1935.

The present invention relates to sequence operation over electrical control lines, and particularly to automatic telephony.

The generally known methods of impulsing and signaling by means of voice frequency currents are based on the sending of one or more impulses having the same frequency or different frequencies, successively or simultaneously, the time of the duration of the signal or of a part of the signal being the time of the duration of the individual impulses.

In the drawings: Fig. 1 shows an undamped train of waves or impulses as delivered at the end of a line imposing negligible damping, with steep initial and end envelope fronts;

Fig. 2 shows the envelope of a damped train of waves as delivered at the end of a short transmission line, with gradually sloping initial and end fronts;

Fig. 3 shows the envelope of a damped train of waves as delivered at the end of a long transmission line, with a gradually sloping initial front and a steep end front;

Fig. 4 is a schematic circuit diagram of the outgoing repeater of the system of my invention, showing the generators and filters for different audio frequencies; and

Fig. 5 is the corresponding incoming repeater.

An impulse transmitted through the loaded line is deformed in the sense that, at the end of the line, the impulse gradually attains its stationary value, and fades gradually out. The enveloping curve (the line connecting the amplitudes of all separate cycles which form one impulse) of an undeformed impulse is shown in Fig. 1, and that of a deformed one in Figs. 2 and 3 of the accompanying drawings, hereinafter more particularly referred to.

Similar deformations also occur even in cases when the impulses are transmitted through lines provided with amplifiers, especially when said amplifiers are provided with impedance networks,

' e. g., filters.

The character of the deformation is not the same during the rise of the voltage as during the fall thereof; but the shape of the enveloping curve at its commencement and its end differ slightly from one another in the case of short lines (Fig; 2). In the case of long loaded lines, however, the rate of increase of voltage at the receiving end during the rise is quite noticeably smaller than the rate of decrease of the voltage (Fig. 3). In the known systems this results in a shortening of the effective period of each impulse, and apart from this shortening of the impulse the moment of operation of the receiving relay is caused to vary.

It is the principal object of the present in- 5 vention to provide a system of impulsing and signaling by means of voice frequency currents, which, in contradistinction to the aforesaid known systems, eliminates the aforesaid drawbacks and renders it possible to transmit success fully with absolute reliability over long and very long lines, as well as short ones, and the invention is based on the fact that the rate of fall of the voltage, at the receiving end does not vary in the same way as the rate of rise thereof. 15

With the aforesaid object primarily in view, it is proposed according to the present invention to provide a system for impulsing and signaling through lines, especially through lines provided with amplifiers, for example for purposes of auto- 20 matic, and semi-automatic telephony, in which signaling is effected by means of voice frequency alternating current, consisting in controlling the duration of the operation of the receiving device dependently on the interval between two suc- 25 cessive falls of the enveloping curves of the voltage curves of two different impulses transmitted.

In accordance herewith, for the purpose of performing an operation of given duration at the receiving end, two pulses of the same or different frequencies are sent, the end of the first pulse determining the beginning of the desired operation and the end of the second pulse determining the end thereof.

As an example of an application of the method above set forth a process for controlling the selectors of automatic exchanges connected by a long line and having mechanical drive will now be described, so as to illustrate how the process is governed by the period elapsing between one fall of the voltage and another one.

The example has been chosen as to meet the rather complicated application of the present invention to the exchanges with continuously driven selectors, it does not limit however in any way the scope of the invention and the possibility of the much easier application to step by step systems.

When the two co-operating exchanges are near one to another the process is carried out by means of D. C. pulsations.

When employing alternating current impulses it should be borne in mind that in this case both the wires which in DC. case serve separately for the transmission of the starting signals and the reverting impulses, are no longer available separately, but they now form one signal circuit through which, both starting and stopping signals and also reverting impulses must be sent. Such processes may be carried out by the employment of different frequencies for all the different kinds of signal and the use of the appropriate receiving filters.

In conformity with the above, the direct current reverting impulses would be changed on the side of the selector into the voice-frequency impulses which on the side of the register, through the filter would be received by the receiving relay, transformed into direct current impulses and then transmitted to the register. The use of a filter is necessary inasmuch as another voicefrequency signal having a different frequency and controlling the process of starting, is transmitted simultaneously through the same line.

In the example described below, the movement of the selector from one position to the next corresponds to half a reverting impulse; in such conditions, both the closure and also the interruption of the circuit of the direct reverting impulses of the selector should be signaled. Two impulses having different frequencies transmitted consecutivelyeach corresponding to the duration of the half of the reverting impulse, may be used according to the present invention, so that the fall of each impulse transmits the commencing of the next half of a reverting impulse.

The diagram of connections of a system according to the invention is shown on Figs. 4 and 5 of the accompanying drawings. The said diagram includes, however, only the essential details of the arrangement according to the system described, details generally known in automatic telephony being omitted. In Fig. 4 is shown the outgoing repeater together with parts of the universally known register and on Fig. 5, the incoming repeater. The arrangements shown of Figs. 4 and 5 appertain to exchanges connected with each other by a line, which may be a physical or phantom line, or may be repeatered or loaded line.

In the following part of this description and in Figs. 4 and 5 the following nomenclature is applied:

KR-controlling relay,

QR-auxiliary controlling relay,

BJrelay receiving reverting impulses,

CRtesting relay,

ST-relay converting the direct starting signal into a voice frequency impulse of 800 cycles per second,

SHl, SH2 and SH3auxiliary relays for ST,

Crcondenser,

FTrline transformer (or phantom transform- F800filter with a range of 800:50 cycles per second,

G300generator having a frequency of 800 cycles per second,

F600 and Fi000filters for frequency ranges of 600150 and 1000150 cycles per second,

EN--receiving relay for a lower frequency (600 cycles per second),

EH-receiving relay for a higher frequency (1000 cycles per second),

EK-receiving and controlling relay,

SE1 and SE2-receiving and starting relays,

CE and SE--electromagnets of the selectors equipment (centering and starting),

TBrelay converting direct reverting impulses into voice frequency impulses of 600 cycles per second and 1000 cycles per second frequency respectively,

G600generator of 600 cycles per second frequency,

Gl000generator of 1000 cycles per second frequency,

GWI and GW2-selectors of the first and the second exchange, Bcontact producing reverting impulses.

After operations generally known in automatic telephony and not forming part of this invention, the selector GWI connects to the corresponding outgoing repeater and circuit 01 is closed:

01: (Fig. 4) resistance, wiper L0 in the selector GWI, CR, relay CR operates After a proper control has taken place the register sets a start-signal in the circuit:

02: (Fig. 4)+, ST, La, GWi, QR, KRb,

The relay QR operates and causes known operations in the register.

The polarised relay ST switches its armature on to STa5. The following circuit is closed:

03: (Fig. 4) SH2b8, STa5, SHi'c-l, SHtaE, SH! pulls up converting the circuit 03 into 04;

04: (Fig. 4) CRaZ, SHla4, SHI, 81130.3,

In this circuit the relay SH I receives holding current. At the same time the following circuit is closed:

05: (Fig. 4) SHZ, SHlcl,

SHZ pulls up and connects the generator G800 to the line, through the circuit:

06: (Fig. 4) G800 terminal 8|, SHQafi, STaS,

SH2c8, FTrl, Crl, F'Irl, G800 terminal 82,

The starting impulse is controlled by the contact S'Ia5 of the quickly acting polarised relay ST.

The starting impulse will reach the second exchange througlr the line, then through the filter F800 it will operate the relay SEI (Fig. 5) which becomes excited, operates its contacts SEiaS and closes the circuit:

07: (Fig. 5)+, SE2, SElaS, SE2 pulls up closing circuit:

08: (Fig. 5) CE, SEZaIO, SEla9, CE operates closing circuit:

09: (Fig. 5)+, CEal I, SE, SE operates and the selector GW2 starts.

When SE2 pulled up a circuit 010 became closed:

010: (Fig. 5) G600 terminal 6|, SE2cl0, TBbiZ, FTT, Cr, FT)", SEZdlO, G600, terminal 62.

A preparatory reverting impulse of a 600 cycles per second frequency was sent to the first exchange; by the action of this impulse the following circuit 011 becomes closed:

011: (Fig. 4) FTrl, SHld4, filter F800, EN, filter F600, SHle4, FTrl; the relay EN switches its armature on to ENa3 and closes a circuit 012: (Fig. 4) ENa3, EK, EK pulls up and closes the circuit for local reverting impulses.

In operating the selector GWZ closes its contact Bal3 (Fig. 5) sending the reverting impulse, the circuit 013 is closed:

013: (Fig. 5)+, Bal3, TB,

The relay TB switches over on to TBaIZ, interrupts the impulse of a 600 cycles per second frequency and connects the generator GIQHG in the circuit analogous to the circuit 010. The fall of the impulse of the frequency of 600 cycles per second is-for the exchange comprising the register-the signal of the commencing of the first half of direct reverting impulse.

The relay EN sends direct reverting impulses in the circuit 014:

014: (Fig. 4)+, ENb3, EKal, Lb, GWI, BJ, the relay BJ pulls up and forms generally known circuits in the register. The relay EK is held in the circuit 015:

015: (Fig. 4) EI-Ib'l, E'Kcl, EK,

The generator GIUQO connected, the relay EH switches on EI-Iai, interrupts the circuit 015, and the relay EK releases; circuit 014 is substituted then by the circuit 016:

016: (Fig. 4)+, EHal, EKbl, Lb, GWI, BJ,

BJ remains operated.

When the contact Bal3 opens (commencement of the second half on the reverting impulse), the.

relay TB (Fig. 5) disconnects the generator GIUOII and connects the generator G600; the fall of the impulse of 1000 cycles per second is-for the exchange comprising the register-the signal of the commencing of the second half of direct reverting impulse, the relay EH will interrupt circuit 016,

the relay BJ will fall back. At least the relay EN will operate and will close an auxiliary circuit 013,

as above.

These operations of the relays will succeed each other periodically in accordance with the incoming reverting impulses until the following stopping circuit is closed in the register:

017: (Fig. 4) KR, controlling circuit between the contact of the registering and controlling electromagnets in the register, contact BJbo (or BjaO), KR pulls up and interrupts the start circuit 02.

I claim:

I. In an automatic telephone system, a source of alternating current of audio frequency, a displaceable actuating switch element, means for initiating the displacement of said element and actuatable by the application from said source and the subsequent reduction to zero at the final terminal point of its envelope of a first train of alternating current waves from said source, and means for stopping the displacement of said element and actuatable by the application from said source and the subsequent reduction to zero at the final terminal point of its envelope of a second train of alternating current waves from said source.

2. In an automatic telephone system, a first source of alternating current of audio frequency, a second source of alternating current of an audio frequency different from the frequency of said first source, a displaceable actuating switch element, means for initiating the displacement of said element and actuatable by the application. from said first source and subsequent reduction to zero at the final terminal point of its envelope of a first train of alternating current waves, and means for stopping the displacement of said element and actuatable by the application from said second source and subsequent reduction to zero at the final terminal point of its envelope of a second train of alternating current waves.

3. In an automatic telephone system, a source of alternating current of audio frequency, a displaceable actuating switch element, means for initiating the displacement of said element and actuatable by the application from said source and the subsequent rise substantially from zero to its steady value at the initial point of its envelope of a first train of alternating current waves from said source, and means for stopping the displacement of said element and actuatable by the application from said source and the subsequent rise substantially from zero to its steady value at the initial point of its envelope of a second train of alternating current waves from said source.

l. In-an automatic telephone system, a first source of alternating current of audio frequency, a second source of alternating current of an audio frequency different from the frequency of said first source, a displaceable actuating switch. ele ment, means for initiating the displacement of said element and actuatable by the application from said first source and subsequent rise substantially from zero to its steady value at the initial point of its envelope of a first train. of alternating current waves, and means for stopping the displacement of said element and actuatable by the application from said second source and subsequent rise substantially from zero to its steady value at the initial point of its envelope of a second train of alternating current waves.

5. In an automatic telephone system, a controlled station comprising a displaceable actuating switch element, a source of alternating current of audio frequency at a point remote from said station, means for transmitting from said source to said station a pair of spaced trains of audio frequency alternating current waves and delivering the same to said controlled station with a steep final envelope wave front, means for initiating the displacement of said element and actuatable by the application and the subsequent reduction to zero at the final terminal point of its envelope of the first of said pair of trains delivered to said controlled station, and means for stopping the displacement of said element and actuatable by the application and the subsequent reduction to zero at the final terminal point of its envelope of the second of said pair of trains.

6. In an automatic telephone system, a controlled station comprising a. displaceable actuating switch element, a first source of alternating current of audio frequency, a second source of alternating current of an audio frequency different from the frequency of first said source, said sources being located at a point remote from said station, means for transmitting from said sources to said station a pair of spaced trains of audio-frequency alternating current waves respectively originating from each of said sources and delivering the same to said controlled station with a steep final envelope wave front, means for initiating the displacement of said element and actuatable by the application and the subsequent reduction to zero at the final terminal point of its envelope of the first of said pair of trains as produced by said first source and delivered to said controlled station, and means for stopping the displacement of said element and actuatable by the application and the subsequent reduction to zero at the final terminal point of its envelope of the second of said pair of trains as produced by said second source and delivered to said controlled station.

ROMAN TRECHCINSKI. 

